The present invention broadly relates to a new and improved method of, and apparatus for, the removal of slag from the metallic melt bath of a melting furnace.
More specifically, the present invention relates to a method of, and apparatus for, removing slag from the metallic melt bath of a melting furnace which houses or takes up the metallic melt in a melt or melting chamber and is provided with means in order to place the melt into motion within the melt chamber. The melting furnace includes a furnace door arranged at one side of the melting furnace.
When melting metals in a melting furnace slag of a specifically lower weight floats upon the surface of the melt. This slag must be removed from this location at predeterminate time intervals, especially before pouring out or tapping of the melt. This operation is commonly referred to as "scraping" of the slag. With conventional slag scraping methods the furnace door of the melting furnace is opened throughout the entire width of the melting furnace and the slag is scraped away from the melt surface with the aid of a sliding or pusher element and deposited into a slag bucket. This slag sliding element, used for performing the slag scraping operation, is located at the end of a long, heavy steel support or carrier which must extend to the boundary wall of the melting furnace and which must be moved in a rather cumbersome manner by means of a fork lift truck or the like.
Since with the conventional techniques the slag is distributed throughout the entire metal bath surface it must be engaged throughout a large surface area by the slag sliding or pusher element, which is positioned by the fork lift truck, and with the melting furnace door completely open. By virtue of the wide opening of the melting furnace door there arise considerable thermal losses. Additionally, there must be engaged and sucked away with the help of a large size suction hood, which extends over the entire width of the melting furnace, the dust or the like which is released and ascends during the slag scraping operation. The large suction cross-sectional area requires a large suction flow or stream with corresponding great energy expenditure.
Improved melting processes use electromagnetic stirrers, briefly known as "ems", which when, appropriately positioned or arranged place the melt into a desired path of motion. Prior art methods which employ such electromagnetic stirrers, however, use such only for moving and intensively admixing the melt. An appreciable improvement of the slag removal operation and a reduction of the energy losses during the scraping operation are not realized by these known melting processes working with electromagnetic stirrers.